The removal of metal filter frits used to retain packing materials in liquid chromatographic columns is frequently necessary, as when the frits become plugged, when new packing material is desired, or when a column void is suspected. This latter situation may be encountered rather frequently when high pressures, such as 3000 psig, are used within chromatographic column supports of small diameter. However, in view of the smallness of these frits, which frits are in the order of 0.125 inch, the removal of the frits has been an extremely difficult and often unsuccessful procedure. While various attempts have been made at devising an apparatus capable of removing this small frit from the tube or column, nevertheless all of these known devices have, to the best of our knowledge, been only partially successful in that they have not permitted the efficient removal of the frit in a safe and dependable manner. Further, none of the known devices can dependably remove the frit without causing damage to the tube or column. Thus, in view of the difficulties encountered in removing these frits, it has been a rather common practice to merely discard the complete column containing the frit therein when one of the above-mentioned conditions is encountered. This maintenance procedure, however, is obviously undesirable since these columns are relatively expensive and thus the need to replace these columns on a rather frequent basis substantially increases the overall operating cost of the chromotographic apparatus. Accordingly, the present invention relates to an improved method and apparatus for removing a small metal filter frit from a tube, such as a liquid chromatographic column, which method and apparatus permits the frit to be easily and efficiently removed from the column so as to permit reusage of the column after installation therein of a new packing and/or frit
It is also an object of the present invention to provide a method and apparatus, as aforesaid, which is equally applicable for use on tubes or columns which permits removal of the metal frit from either end of the column, irrespective of whether or not the column has external ferrules thereon.
A further object of the present invention is to provide a method and apparatus, as aforesaid, which is extremely simple and is manually manipulated to provide for efficient yet precise removal of the frit from the column without damaging the column or the packing.
Other objects and purposes of the invention will be apparent to persons acquainted with devices of this type upon reading the following specification and inspecting the accompanying drawings.